"Diffusion of fissile inventory in AGR-1 Triso fuel particles as a function of temperature & silver retention" Rachel Seibert, Jeff Terry, Tyler Gerczak, Kurt Terrani, John Hunn, Fred Montgomery, Charles Baldwin, Transactions of the American Nuclear Society Vol. 118 2018 1486-1487 Link | ||
"Investigation of thermal aging effects on the tensile properties of Alloy 617 by in-situ synchrotron wide-angle X-ray scattering"
Xiang Liu, Kun Mo, Yinbin Miao, Kuan-Che Lan, Guangming Zhang, Wei-Ying Chen, Carolyn Tomchik, Rachel Seibert, Jeff Terry, James Stubbins,
Materials Science and Engineering: A
Vol. 651
2016
55-62
Link
The nickel-base Alloy 617 has been considered as the lead candidate structural material for the intermediate heat exchanger (IHX) of the Very-High-Temperature Reactor (VHTR). In order to assess the long-term performance of Alloy 617, thermal aging experiments up to 10,000 h in duration were performed at 1000 °C. Subsequently, in-situ synchrotron wide-angle X-ray scattering (WAXS) tensile tests were carried out at ambient temperature. M23C6 carbides were identified as the primary precipitates, while a smaller amount of M6C was also observed. The aging effects were quantified in several aspects: (1) macroscopic tensile properties, (2) volume fraction of the M23C6 phase, (3) the lattice strain evolution of both the matrix and the M23C6 precipitates, and (4) the dislocation density evolution during plastic deformation. The property?microstructure relationship is described with a focus on the evolution of the M23C6 phase. For aging up to 3000 h, the yield strength (YS) and ultimate tensile strength (UTS) showed little variation, with average values being 454 MPa and 787 MPa, respectively. At 10,000 h, the YS and UTS reduced to 380 MPa and 720 MPa, respectively. The reduction in YS and UTS is mainly due to the coarsening of the M23C6 precipitates. After long term aging, the volume fraction of the M23C6 phase reached a plateau and its maximum internal stress was reduced, implying that under large internal stresses the carbides were more susceptible to fracture or decohesion from the matrix. Finally, the calculated dislocation densities were in good agreement with transmission electron microscopy (TEM) measurements. The square roots of the dislocation densities and the true stresses displayed typical linear behavior and no significant change was observed in the alloys in different aging conditions. |
||
"Local atomic structure of Pd and Ag in the SiC containment layer of TRISO fuel particles fissioned to 20% burn-up"
John Hunn, Rachel Seibert, Kurt Terrani, Jeff Terry, Daniel Velazquez, Charles Baldwin, Fred Montgomery,
Journal of Nuclear Materials
Vol. 500
2017
316-326
Link
The structure and speciation of fission products within the SiC barrier layer of tristructural-isotropic (TRISO) fuel particles irradiated to 19.6% fissions per initial metal atom (FIMA) burnup in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) was investigated. As-irradiated fuel particles, as well as those subjected to simulated accident scenarios, were examined. The TRISO particles were characterized using synchrotron X-ray absorption fine-structure spectroscopy (XAFS) at the Materials Research Collaborative Access Team (MRCAT) beamline at the Advanced Photon Source. The TRISO particles were produced at Oak Ridge National Laboratory under the Advanced Gas Reactor Fuel Development and Qualification Program and sent to the ATR for irradiation. XAFS measurements on the palladium and silver K-edges were collected using the MRCAT undulator beamline. Analysis of the Pd edge indicated the formation of palladium silicides of the form PdxSi (2?=?x?=?3). In contrast, Ag was found to be metallic within the SiC shell safety tested to 1700?°C. To the best of our knowledge, this is the first result demonstrating metallic bonding of silver from fissioned samples. Knowledge of these reaction pathways will allow for better simulations of radionuclide transport in the various coating layers of TRISO fuels for next generation nuclear reactors. They may also suggest different ways to modify TRISO particles to improve their fuel performance and to mitigate potential fission product release under both normal operation and accident conditions. |
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"Pertechnetate-Induced Addition of Sulfide in Small Olefinic Acids: Formation of [TcO(dimercaptosuccinate)2] 5- and [TcO(mercaptosuccinate)2] 3- Analogues"
Silvia Jurisson, Kimberly Reinig, Rachel Seibert, Daniel Velazquez, Jakob Baumeister, Firouzeh Najafi Khosroshahi, Wei Wycoff, Jeff Terry, John Adams, Carol Deakyne,
Inorganic Chemistry
Vol. 56
2017
13214-13227
Link
Technetium-99 (99Tc) is important to the nuclear
fuel cycle as a long-lived radionuclide produced in ∼6% fission
yield from 235U or 239Pu. In its most common chemical form,
namely, pertechnetate (99TcO4
−), it is environmentally mobile.
In situ hydrogen sulfide reduction of pertechnetate has been proposed
as a potential method to immobilize environmental 99TcO4
−
that has entered the environment. Reactions of 99TcO4
− with
sulfide in solution result in the precipitation of Tc2S7 except when
olefinic acids, specifically fumaric or maleic acid, are present; a
water-soluble 99Tc species forms. NMR (1
H, 13C, and 2D methods)
and X-ray absorption spectroscopy [XAS; near-edge (XANES)
and extended fine structure (EXAFS)] studies indicate that sulfide adds across the olefinic bond to generate mercaptosuccinic
acid (H3MSA) and/or dimercaptosuccinic acid (H4DMSA), which then chelate(s) the 99Tc to form [99TcO(MSA)2]
3−,
[
99TcO(DMSA)2]
5−, or potentially [99TcO(MSA)(DMSA)]4−. 2D NMR methods allowed identification of the products by
comparison to 99Tc and nonradioactive rhenium standards. The rhenium standards allowed further identification by electrospray
ionization mass spectrometry. 99TcO4
− is essential to the reaction because no sulfide addition occurs in its absence, as determined
by NMR. Computational studies were performed to investigate the structures and stabilities of the potential products. Because
olefinic acid is a component of the naturally occurring humic and fulvic acids found in soils and groundwater, the viability of in
situ hydrogen sulfide reduction of environmental 99TcO4
− as an immobilization method is evaluated. |
||
"Structural Characterization of Fission Products in Irradiated TRISO Fuels using Transmission Kikuchi Diffraction, Transmission Electron Microscopy, and Synchrotron X-ray Absorption Spectroscopy" John Hunn, Chad Parish, Jeff Terry, Rachel Seibert, Charles Baldwin, Kurt Terrani, Microscopy & Microanalysis Vol. 23 2017 1118-1119 Link | ||
"Study of Irradiated Mod. 9Cr-1Mo Steel by Synchrotron XAS" Hasitha Ganegoda, Daniel Olive, Jeff Terry, Yulia Trenikhina, Meimei Li, Stuart Maloy, Transactions of the American Nuclear Society Vol. 102 2010 855 Link | ||
"Study of irradiated mod.9Cr–1Mo steel by synchrotron extended X-ray absorption fine structure"
Hasitha Ganegoda, Meimei Li, Stuart Maloy, Jeff Terry, Yulia Trenikhina, Daniel Olive,
Journal of Nuclear Materials
Vol. 441
2013
674-680
Link
Synchrotron extended X-ray absorption fine structure (EXAFS) spectroscopy measurements were performed to study the dose dependence of and alloying effects on irradiation-induced changes in the local atomic environments in a mod.9Cr–1Mo ferritic-martensitic steel. The measurements were carried out at room temperature on non-irradiated and irradiated specimens exposed to 1, 4, and 10 displacement per atom (dpa) at 40–70 °C. The EXAFS data for Fe, Cr, Mo, and Nb K-edges were recorded, and the local structure close to the X-ray absorbing atom was determined. Irradiation caused significant reductions in peak amplitude in the Fe, Mo and Nb K-edge Fourier transformed EXAFS. The data showed a systematic decrease in coordination number of neighbor atoms with increasing irradiation dose, and the dose dependence of the coordination loss was dependent on the specific element. The measured damage around Fe sites can be correlated with the dpa value, while the loss of near neighbors around Mo saturated at ~1 dpa. The coordination in the Fe matrix was reduced less by irradiation than either the coordination of Mo in solution or Nb in carbides. It was demonstrated that EXAFS can provide a detailed, atomic level description of radiation damage in complex alloy systems |
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"TEM and XAS investigation of fission gas behaviors in U-Mo alloy fuels through ion beam irradiation" Kun Mo, Walid Mohamed, Jeff Terry, Di Yun, Journal of Nuclear Materials Vol. 494 2017 165-171 Link | ||
"Using a spherical crystallite model with vacancies to relate local atomic structure to irradiation defects in ZrC and ZrN"
Todd Allen, Hasitha Ganegoda, Daniel Olive, Jeff Terry, Yong Yang, Clayton Dickerson,
Journal of Nuclear Materials
Vol. 475
2016
123-131
Link
Zirconium carbide and zirconium nitride are candidate materials for new fuel applications due to several favorable physicochemical properties. ZrC and ZrN samples were irradiated at the Advanced Test Reactor National Scientific User Facility with neutrons at 800 °C to a dose of 1 dpa. Structural examinations have been made of the ZrC samples using high resolution transmission electron microscopy, and the findings compared with a previous study of ZrC irradiated with protons at 800 °C. The use of X-ray absorption fine structure spectroscopy (XAFS) to characterize the radiation damage was also explored including a model based on spherical crystallites that can be used to relate EXAFS measurements to microscopy observations. A loss of coordination at more distant coordination shells was observed for both ZrC and ZrN, and a model using small spherical crystallites suggested this technique can be used to study dislocation densities in future studies of irradiated materials. |
" Fission Product and Actinide Distribution in the Sic Layer of Fissioned Triso Fuel Particles" Tyler Gerczak, John Hunn, Keith Leonard, Jeff Terry, 2017 ANS Annual Meeting [unknown] | |
"Damage Structure Evolution in Ion Irradiated UO2" Todd Allen, Jian Gan, Mahima Gupta, Andrew Nelson, Jeff Terry, TMS 2014 February 16-20, (2014) | |
"Diffusion of fissile inventory in AGR-1 Triso fuel particles as a function of temperature & silver retention" Rachel Seibert, Jeff Terry, Tyler Gerczak, Kurt Terrani, John Hunn, Fred Montgomery, Charles Baldwin, The American Nuclear Society Annual Meeting June 17-21, (2018) | |
"Materials Characterization using the Center for Synchrotron Radiation Research and Instrumentation (CSRRI)" Jeff Terry, 2017 ANS Annual Meeting [unknown] |
This NSUF Profile is 40
Authored an NSUF-supported publication
Presented an NSUF-supported publication
Submitted 3+ RTE Proposals to NSUF
Awarded an RTE Proposal
Collaborated on 3+ RTE Proposals
Reviewed 10+ RTE Proposals
Atom probe tomography of high burn-up mixed oxide fuel - FY 2014 RTE 3rd Call, #507
Effect of Heavy Ion Bombardment on UO2 thin films under various conditions of irradiation dose, temperature and actinide surrogates - FY 2011 APS, #301
Investigation of the chemical state of Ag and Pd in SiC shell of irradiated TRISO particles via XAFS - FY 2014 APS, #473
Microstructural characterization of ~7% burn-up MOX fuel - FY 2018 RTE 1st Call, #1179
Si-Ni-Mn clustering in irradiated Fe-9Cr oxide dispersion strengthened alloy - FY 2015 RTE 1st Call, #540
Study of an Irradiated Ferritic Steel by Synchrotron XRD and XAS - FY 2010 APS, #230
Synchrotron XAS and EXAFS Study of Technetium-99 Relevant to the Nuclear Fuel Cycle - FY 2014 APS, #448
Synchrotron X-Ray Characterizations of Advanced Accident-tolerant Cladding - FY 2014 APS, #463
TEM investigation of the SiC containment layer of irradiated nuclear fuel particles - FY 2016 RTE 2nd Call, #640
X-ray characterization of fission gas bubble pressure in ion irradiated metallic alloy fuels - FY 2013 APS, #388
The Nuclear Science User Facilities (NSUF) is the U.S. Department of Energy Office of Nuclear Energy's only designated nuclear energy user facility. Through peer-reviewed proposal processes, the NSUF provides researchers access to neutron, ion, and gamma irradiations, post-irradiation examination and beamline capabilities at Idaho National Laboratory and a diverse mix of university, national laboratory and industry partner institutions.
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